1. Field of the Invention
The present invention relates to an ultrasonic reactor water level measuring device that uses ultrasonic waves to measure a water level of a reactor such as a boiling water reactor. The invention also relates to a method for evaluating the soundness of the ultrasonic reactor water level measuring device.
2. Description of the Related Art
An ultrasonic water level meter that includes an ultrasonic probe, a time meter and a water level calculator is known in the art. The ultrasonic probe transmits an ultrasonic signal into a fluid. The time meter measures a propagation time between the transmission of the ultrasonic signal to the surface of the fluid within a waveguide, and return of the ultrasonic signal from the surface of the fluid. The water level calculator calculates a water level on the basis of the propagation time and executes temperature compensation. Since the propagation time is a round-trip propagation time, the propagation time is converted into a one-way trip propagation time. The water level is calculated by multiplying the one-way trip propagation time by the speed of a sound within water with a compensated temperature (for example, JP-2011-180052-A).